Patient-Specific Bone Implant Density Control in 3D Printing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current orthopedic implants lack patient specificity and biological interaction, leading to issues such as stress shielding, bone resorption, and poor osseointegration due to mismatched modulus of elasticity and non-biodegradability, necessitating the development of implants with variable density and surface texture for improved bone regeneration.
Innovation Solution
A method for 3D printing patient-specific bone implants using a foamable thermoplastic composition comprising bioactive agents and chemical foaming agents, where the 3D printing temperature is adjusted to achieve desired density and modulus of elasticity, mirroring the patient's bone properties, and incorporating bioactive agents like hydroxyapatite for enhanced biological interaction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional orthopedic implants are used, then structural support is provided, but stress shielding and bone resorption occur due to mismatched modulus of elasticity
Solution Approach 1:
The patent applies parameter changes by varying the printing temperature during 3D printing to control the density and modulus of elasticity of different regions of the implant. By adjusting temperature parameters, the implant achieves a gradient structure that matches the varying modulus of elasticity of natural bone, thereby reducing stress shielding and bone resorption.
Solution Approach 2:
The patent implements local quality by creating regions with different densities and material properties within the implant structure. Different portions of the implant are printed at different temperatures to achieve local variations in modulus of elasticity, allowing the implant to better match the heterogeneous structure of natural bone and reduce harmful stress shielding effects.
2Duration of action of stationary object
If non-biodegradable materials are used for implants, then long-term structural support is achieved, but poor osseointegration and need for subsequent surgery occur
Solution Approach 1:
The patent uses parameter changes by controlling printing temperature to create a gradient structure where certain regions have enhanced porosity and surface characteristics that promote bone ingrowth and osseointegration, while maintaining overall structural integrity for long-term support.
Solution Approach 2:
The patent applies porous materials by creating controlled void spaces and porous structures within the implant through temperature-controlled 3D printing. These porous regions facilitate bone ingrowth and improve osseointegration, while the overall implant structure maintains sufficient strength and longevity.
3Object-affected harmful factors
If implants with variable density are produced, then bone regeneration is improved, but manufacturing complexity increases
Solution Approach 1:
The patent resolves the contradiction by using temperature as a control parameter during 3D printing to achieve variable density structures. By simply adjusting the printing temperature, the system can create different density regions without requiring complex post-processing or multiple manufacturing steps, thus improving bone regeneration while keeping the manufacturing process relatively simple.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method enables the production of implants with variable density and surface texture, improving bone regeneration and reducing the need for subsequent surgical procedures by creating implants that more closely match the patient's bone properties, enhancing osseointegration and reducing negative impacts on surrounding tissue.
Implementation Method 1
between about 0.5% and about 10% chemical foaming agent by weight
Implementation Method 2
causing each of the cooling element and the heating element to cooperate to heat the thermoplastic polymer composition to the temperature that corresponds to the desired density
Data Source
AI summary
A method for 3D printing a patient-specific bone implant having variable density, in various aspects, comprises: (1) providing a thermoplastic polymer composition comprising: (A) between about 20% and about 50% bioactive agent by weight; (B) between about 0.5% and about 10% chemical foaming agent by weight; and (C) balance structural polymer by weight; (2) receiving, by computing hardware, a scan of a bone, the scan comprising at least a 3D image of the bone and radiodensity data for the bone; and (3) causing, by the computing hardware, a 3D printer to form the patient-specific bone implant from the 3D image using the thermoplastic polymer by modifying a 3D printing temperature of the 3D printer during printing of the patient-specific bone implant such that each portion of the patient-specific bone implant is produced at a temperature that corresponds to a desired density defined by the radiodensity data for the bone.